2003 Exhaust noise

[atkijaco]

I have a 2003 EB 4x4 115K.

Upon startup when engine is cold I get a "blat blat blat" noise from the exhaust. Almost like it has a glass pack but not as loud and it goes away once in 5-20 seconds. Some times it is brief and slow sounding and other times it last for 20 seconds and is rapid.

Any ideas? Cat starting to plug maybe?

 

[stamp11127]

Have someone start it up for you while you are listening so that you can pinpoint the location of the sound. It may be a loose connection that closes once the system is hot or a problem with the exhaust manifold(s).

 

[hammerg26]

Has that sound on an old Suburban - was caused by oil draining out of the filter (dealer used wrong filter). Changed your oils recently?